Korean Patent No. 10-0799028 (registered on Jan. 22, 2008) discloses “Improved closed suction catheter assembly adaptor and system containing the same”.
The closed suction catheter assembly adaptor includes a housing defining an inner chamber and having a first end configured to be removably engaged to an end of an artificial airway tube, and a second end configured to communicate with an end of a closed suction catheter system, wherein the housing further includes an internal structure radially inwardly extending from the housing and defining an air passageway between the housing and the artificial airway tube, such that air is inhaled and exhaled by the breathing patient through the artificial airway to which the adaptor is attached.
The closed suction catheter is provided with a push-type suction control valve at a position opposite to the adaptor. However, the push-type suction control valve cannot control the suction pressure, and the suction pressure gradually decreases during the course of the operation and thus the suction pressure cannot be maintained uniformly.